Electric clock



May 24, 1932. L. J. STERN 1,360,120

ELECTRIC CLOCK Original FilerI April 18, 1924 3 Sheets$heet 1 INVENTOR. kewls S'I'BYYL v ATTORNEYf.

May' 932.

L. J. STERN ELECTRIC CLOCK 3 Sheets-Sheet 2 Original Filed April 18, 1924 INVENTOR. fiwlf) J fitevn ATTORNEY].

May 24, 1932. J. STERN 1,860,120

ELECTRIC CLOCK Original Filed April 18, 1924 5 Sheets-Sheet 3 INVENTOR. Lemma 1 Si ATORNEYL Patented May 24, 1932 LEWIS J. surnnmor new YORK, N. Y.

ELECTRIC CLOCK Original application filed April 18, 1924, Serial No. 707,321. Dividedand this application med December 21, 1928. SerialNo. 327,662.

for repair and replacement of parts, etc. and which is generally more efficient 1n construction and operation. To this end my improve ments consist of various features of construction which will more clearly appear from the detail description given below taken in connection with the accompanying draw-- ings which forma part of this specification.

This application is a divisional application .from my pending application, Serial No;

""707321, filed April 18, 1924, for electric clocks. V

In the drawings Fig. 1 is a perspective of a clock located in, the dash'of an auto- .mobile, the clock embodying my improve- 'ments in a preferred form thereof. Fig.2

is a front elevation of the clock parts with the outer casing, dial etc. removed. Fig. 3

is an elevation of the parts shown in Fig. 2,

.taken at right angles thereto. Fig. 4 is a 'rear elevation of the parts shown in Figs. 2

and 3. Fig. 5 is a vertical section taken on T the line 55 of Fig. 4, the surrounding casing and the parts for securing the clock to .the dash-board being also shown insection;

therewith. Fig. 6 is a Viewv similar to Fig. 4 with the electro-magnet windings removed.

Fig. 7 is a View showing someof the parts, 1

of the plate 11. which willnot. pass through the section being taken on the-line 7-7 of Fig. 6. Fig. 8 is a top plan view of the clock secured to the dash-board." Fig. 9 is a detail section through the axis of the main arbor of the clock showing the method of I securing the clock hands thereto. Fig. 10 is a rear view of the clock movement'and 11 is a side view of the same. Referring to the drawings, 1 represents the dash-board of an automobile for use on whichthe clock is specially adapted, although it 4 1 will be found useful in many other situations.

2 represents a cylindrical casing closedatone fiend by the integral plate or end 3 so that movable therefrom is a fla g rim 4 adapt ed to hold the front glass 5 through which the clock face is visible.

Within thercasing is a circular frame plate V 6, having secured to the front thereof a fiat 1 r ng 7 of the same outside diameter. Rigidly secured tothe plate 6 0n the otherside therei of is another circular frame plate '8. The plates 6,7, and 8 are rigidly secured'together in parallel spaced relation by posts and spacingfbushings 9.

The clock movement (shown separately in Figs. 10 and 11) comprises two spaced apart circularplates 10 andjll. These plates are held rigidly secured to one another'by' confi ing posts 12 with the clock movement-j 7 gears and arbors therebetween and carried.

thereby, the main arbor being indicated at 13, the hair spring at 14: and the slow afndlfast. regulating lever atlia having the usual loop 15 engaging the hair spring. On the same 1 axisas the main arbor is a sleeve 16 which sleeve extends through the rear plate l0 and carries a ratchet'wheel 17. -The parts are so arrangedthat upon a spring tending to rotate the ratchet wheel the clock movement will be operated.

PATENT: re r The main frame plate 6 is centrally apertured as indicated by the line 18 on Fig. 2 the aperture being sufficiently large to receive the clock movement, the rear plate 10 beingsmall enough to pass therethrough, The edge of the aperture is rabbeted to receive the edge the aperture and the whole clock movement is rigidly secured in place to the main frame plate 6 by screws 19 screw-threaded in'the;

" plate 6 but the heads of which overlap the y edge ofthe plate llt'o hold the same and: the. whole clock movement firmly in place and rigid with the plate'6'. Thus the whole clock movement unit as shown in Figs. lO'and 11 may be easily removed from the frame'plate 6 by merely removing the screws19. The rear frame plate 8 is also provided with a central circularaperture large enough to permit the ratchet Wheel 17 to pass therethrough so that when the parts are in place the ratchet will be on the rear side of the plate.

The dial of the clock is shown at 20 and this is secured to'the ring 7 in front of the Y main frame plate 6 by bending certain projections from the periphery of the dial'about the outer edge or periphery of the ring 7 as shown at 21 (see Fig. 5). Extending through the dial 20 is a sleeve 22 (see 9) having fixed on the front end thereof the hour hand 23 and on the inner end thereof a gear 24. Between the gear 24: and the dial 20 is a leaf spring 25a which tends to force the gear 24 away from the dial. When the dial is put in place the sleeve 22 is slipped over the front end of the arbor 13 with the gear 24 maintained in mesh with a gear 25 (see F ig. 3) which is rigid with a gear 26 which in turn meshes with a gear 27 secured on the main arbor 13. The end of the arbor 13 is made square or non-circular in cross- 7 section and the minute hand 28 is provided at its axis with a corresponding aperture adapted to fit over this portion so as to be;

turned thereby; The minute hand 28 is held rigidly on the arbor by the head ofa screw 29 which is screw-threaded into the end of the arbor 13. As the clock is operated and the arbor 13 is turned, the minute hand 28 turns with it at the same speed. The sleeve 22 is capable of turning on the arbor 13 and by means of the reducing gears 27, 26, 25 and 24is drivenone-twelfth as fast asthe arbor 13 and the minute hand whereby the hour hand 23 secured on the sleeve is driven at the hourly speed. In order to more firmly. hold the sleeve 22 with the hour hand, on'the arbor 13, the arbor 13 has. a reduced cross-section as at 30 and the sleeve 22 is pressed inwardly thereat so that it :is effectively prevented from slipping longitudinally on the arbor.

Thus both hands are firmly held in place and can not bejarred off as would otherwise be likely when the clock is subjected to excessive jarring such as occurs in use on automobiles. I

31 is a bracket attached to rear face ofthe circular frameplate 8 (see Figs. 4 and 6) and ournaled between the end of the bracket and the plate 8 a ivot 32 carrying an an mature 33 adapted to be attracted by thepolar ends 3% of electro-magnets 35. The armature 33 carries rigid thercwi h an arm 36 extending away from the pivot 32' at rightlangles to the armature; Pivotally mounted onthe end of the arm 36 is a' pawl 37, normally pressed a ainst the teeth of theratchet 17 bya coiled tension spring 38. One "end of'the spring 38 is secured to a fixed bracketon theplate 8 and the other end of the spring issecured to a hook l0 on thepawl 37 ashort distance from the point where the pawl is piv oted to the arm 36. The spring is so positioned that it not only tends to rotate the pawl'about-its pivot andinto engagement with the teeth of ratchet wheel 17, but also the spring38 pulls on the arm 36 in a direction to cause the pawl to rotatethe ratchet,

Wheel 17 and operate the clock. As the ratchet wheel so rotates the armature 33 swings away from the pole pieces 3l.

Pivotally mounted between a bracket 41 l and the plate 8 is a switch lever 4L2 having an upturned lug 43 to which is connected one end of a coiled tension spring l i, the other end of the spring l i being connected to a.

projecting arm 45,011 the armature 33. The

i switch member 42 is provided with an arm 46 between the bracket l8 and the plate8about a pivot 4-9 is a switch contact member 50 carrying an electrical contact at 51 suitably insulated from the member '50 but electrically connected 1n clrcuit with the magnets by means of a coil of spring wire conductor 52."

The member 50 has an. arm 53 extending in the opposite direction from the pivot, which arm is bent over at itsouter end and extends 2 into a slot 54 in the face of the plate 8 thereby limiting the movement of the member'50 aboutits pivot 49 to a very slight movement determined by the play which the arm 53 has in the slot 54. The contact 51 is preferably made of silver while the switch arm 42 carries'an electrical contact 55 of silver or other suitable metal. The magnets 35 are electrically connected in series with one another by conductor 56. One terminal 57 of the two magnets is'connected to one side of a source ofelectrical energy such a storage battery while the other terminal of the battery is grounded on the metal parts ofthe apparatus.

Assuming the parts tobe in the position shown in Fig-4t, the spring 38 will be under 38, being retarded by the escapement mechanism of the clock movement, thearmature simultaneouslygradually moves away from the pole pieces 34land carries withit the end of spring 44: which attached tothe lug 45. When the line between the two ends of the spring 4a is swung over to the other side of the 42 about its pivoting point causing the corn tact 55 to swing into electrical contact .engagement with the contact 51 and make contact therewith as shown in Fig. 6) with more or less of a sliding contact so as to keep the engaging faces of the contacts clean. To facilitate this the contact member 51 is carried bythe pivotally mounted arm 50 and resiliently held toward'the contact 55 by the weak spring 52 so that when the switch member 42 is swunginto engagement with the contact-51 it causes a slight movement of the member 50 about its pivot thereby permitting the contact faces to slide or rub over one an 1,seo,12o.

other in order to insure good electricall:con-= r k a i-Thesescrew-threadedend portions extend When the contact which is electricallyi tact.

grounded to the metal parts of the apparatus engages the contact 51, the circuit is com' pleted through the magnets whichcauses the armature 33 to be attracted and the arm'36d again moved to the position shown in Fig.4

which again places the main spring 88 uning the ratchet in a different "place.v After, the armature has been attracted certain;

distance toward the pole pieces 34 butbefore actually coming against the pole piece,.thef line between the two endsof the spring 44. passes to the other side-of the axis about which the switch member 42 is" pivoted,

whereupon the spring 44 snapsthe switch 42 open and'causes the switch contact 55300 be quickly withdrawn fromthe contact 51. The

resulting backward opening movement of the switch is limited, by the arm 46 engaging the bracket, post 47' which also serves as a back stop for thearmature 33 which is drawn thereto by the main spring 38 when the mag nets are disconnected fromflthe source of elec-L trical energy. The parts may be so adjusted that the switch member will automatically" close the circuit'through the magnets about,

once every minute but it will be seen that as soon as the circuit is closed, the armature is immediately attracted and places the spring 38 substantially under its initial tensionand immediately opens the switch, so that the spring will again perform its function of supplying the necessaryforce to operate the clock or time piece. The armature 33 at its outer endcarries an arm 58 extending toward the frame plate 8. This arm is so positioned,-that, should the spring 44 fail to open the switch when the armature is attracted by the electro-magnet, the arm 58 will engage the switch lever 42 and kick the switch open."

The switch member thus intermittently controls the energization and deen ergizationof the electro-magnets and the spring 44 connected atone end to the switchmember at a point on one side of its pivot and at the other end to a point on the other side of the pivot and to the armature, is adapted to'throw the switch in each direction in'response to the movement of the armature in each direction, and also to hold the switch at the end of its travel in each direction until the armature has moved a substantial distance from the end of its travel. l

In order to secure the parts firmly in the casing 2, 3, posts 60 are'rigidly secured to the frame '6 and extend rearwardly there-- from. The plate 8 isvcut away at the edges to accommodate these posts. The posts'tiO are provided with end portions 61 reduced thereonto-hold all the parts rigidly in the cross-'sectionland which are. screw-threaded.

through holes-in theaback3 of the casing and 1 nuts ;62 are applied thereto and screwedillp casing; It will be seen that back 3 acts as a f rear frame plateri'gidly connectedto the front frame plateG-by theflpostsftiO andlthe jelectro-magnetic-means with its associate dl parts for' operatmgthe; cloclemovement are carried betweenthese plates and bythe front plate 6 independently ,ofthe'fclock movement,

i 'f he glass 5 is removed ,byunscrew} ing the rim4. i w

I In order spindle 64 a is" provided. This I spindle is journaled in one of the posts '65 .which&sup-' port and rigidlyconne'ct the core. 66 ofthe? I spindle 64 extends, through'the back 7 has a knob 67 rigidly screwedthereon for the purposev of conveniently turning the same; V from the back oftheclockJ At its opposite" i endthe spindle '64 has""secured thereto a forked member 68, the forkedpart ofQwhich i back and forth to similarly move and adjust the slow andi'ast regulating lever arm 14a, of the clock-movemeiiti twill-be noted,l1ow-- -electro -magnet upon theirame plate '8; The i of and ever, that the spindle and fork arenot oth er-e a wise connected; to the clock ,mfovement .unit

but are carried by the framepl'a-tesand the.

clock movementunit; may be removed without When the clock movement nail;- is removed from the frame plates 7 and 8 it simply slips: out of the fork. The1lever 14a has a forg wardly projecting arm 69 which extends into a slot inthe dial 20 so asto be visible from 5 the frontofjthe clock and thu'siindic'ateon the face ofthe clock-theeiitent to which ad 1 V L justmen-t has been made. a

In order to provide means-forfadjusting the setting ofthe hands fromithebackof the clock, thereis providedjanotherfsimilar spin: die 70 'journaleel in a bushing] 1' secured rig; idly in'the frame'plate 8. The spindle 7Oi-is capable of sliding axially in thewbllshing and clockfiAtgits front e'nd the spindle 70" has rigidly seciired thereto a small. pinion :74.

Surrounding the spindle ZOfbet-ween the'pinf ion .74and thebuslii'ng '7 1 'is 'a;coi-led coinpre's- I sion spring I; which: normally tor-ices the 10's inany way disconnecting the spindle and its I fork fromtheir support or from one another. I

spindle '70 toward the front of the dial 20.

until the pinion 74 is stopped'by and lies against the be a a 7G represents-a layer pinion 3ournaled on the front face f the plate 11' 01 the clock n'iovement unit and meshes with the reducing gear thereon. j To set the hands of the clock from the hack the operator merely grasps the knob T73 and pulls the spindle'l'tl rearwardly until the pinion'i tcoines in the same plane and 'meshes: with the "pinion T6 and then turns the knob ande spindle thereby turning the pinions and gears/M, 76, 2:6, 25,

Qiand the'hand gearfl? and main ar- 'b'or"13and hand 28 carried thereby, 1 Upon releasing the knob '73 the spring 75 forces the pinion 74 back against the back of the dial and out of engagementwith the pinion It will be noted thatthe spindle 70, like the spindle 64-, is journaled in parts carried by the frame 8 and is located at theperiphery of the clock movement unit so" that it-passes along one side of the same andnot therethrough and the plates 10 and ll of theclock movement unit arecut awayat "7?, whereby the clock movement unit-maybe removec from the rest of th'e'parts shown in Figs. 2 and 3-without disturbing the spindle 70 or removing the pinion Ttherefrom. v

In securing this clock on the dashboard the clock, assembled in the casing, is slipped into' the clock hole inlthe dash until the rim 4 comes up against the front o fthe dash. 'The widely diflerent forms.

back 3 of the casing has two diametrically opposite screw-threaded posts 78 secured rigidly thereto "and extending rearwardly there-s from, A'bracket 79 having'two inwardly extending legs 80, is provided with two holes in its back portion, corresponding to the posts 78, and this is slipped on with the posts 78 extending through these holes, until the pointed ends of the legs 80, on diametrically oppositesides of the clock, engage the back ofthe dashboard. Nuts 81 are then screwed upon therposts 7 8 whereupon the whole clock is held rigidly on the dash. The back?) is also cuitthrough the electromagnet, a spring havo ing one end connected to the armature at a point located on oneside of the pivot of said a member andthe other end'of said springcon-V I neoted to a point of the said member located 7 on the opposite side of said pivot, whereby the movement of the armature causes the positions, and means on the armature adapt ed topositively movethe member to its opencircuit position should said 'spring fail to so I move it. a

member to move to its openand closed circuit ".2. In an electric-clock of the typexwhereinl;

a clock movement unit is operated by an ar} a mature controlled by an electromagnet, a

member pivotally'mounted adjacent to said armature adapted to open and close the-circuit through the' electromagnet, resilient: means having a part connected to the arm'a ture at apoint located on one side ofthe pivot ofsaid member and another part ofsaid resihent means connected to a point of said member located on the opposite side of its 7 said pivot, whereby the movementof the armature causes the member to moveto its open and closed circuit positions, associated with means onthe armature adapted to positively move the said member-should sa-id'resilient means vfail to so move it. I

V LEWIS J STERN.

provided with ahole through which an eleci trical conductor is inserted ,to connect the claims y Letters Pat tv What I claim as newjand desireto secure 1. In an electric clock of the type wherein I a clock movementunit is operated by an armature controlled by an electromagnet, a

member pivotally 'mounted'adj acent to said armature adapted to open and close the cir- 

